It was also the highest total for any October opening in history and a number that -- heavens to Betsy -- equaled the amounts for all the other films in the box-office top 10 ... combined. "Paranormal's" ticket receipts this weekend put it on pace to easily top the $85-million cumulative total of the second movie and almost certainly the $107-million total of the first film as well. Many sequels lose steam by their third go-round. But Americans (and plenty of other people around the world) are seemingly more eager than ever to plunk down money to watch Katie get haunted, spooked and tormented.

Of course, this weekend only tells a small piece of the story. The larger play for "Paranormal" producers and studio Paramount Pictures lies with morphing the brand from a one-off, out-of-nowhere discovery two years ago into a long-running, durable franchise that serves as the holy grail for any movie studio. (Although there's no official word of a fourth movie, you can bet your last VHS tape there'll be one.)

The gold standard for this is "Saw," which for seven straight Octobers beginning in 2004 was one of the most popular of modern movie franchises. It was a triumph of the slow-but-steady variety -- no film grossed more than $90 million, but, save for the sixth one, took in at least $45 million each time out, a solid feat in an era when big franchises often fly too close to the sun and burn up.

Certainly "Paranormal" would seem well-positioned to carry on the "Saw" mantle: It has the brand name, the fan base and, now that "Saw" as wound down its run, the Halloween period to itself. Already the series is on track to take in a good deal more than the first three "Saw" movies.

But there are also some big distinctions between the showy splatter of Jigsaw and his victims and the haunted-house creeps of Katie and her family. Perhaps the biggest one is that "Paranormal" relies on the novelty of a format -- found footage -- and novel formats tend to wear out their welcome pretty quickly, especially as the knockoffs start to fly.

With "Saw," there was something ritualistic, even cathartic (in that torture-porn, excessive-violence sort of way) about watching characters get brutalized every Halloween, a kind of cinematic candy corn. But "Paranormal" relies as much on narrative and the conceit of individual films, which is a lot less easy to churn out every year. There's no one reason a horror franchises prospers, but it's always seemed to me that "Saw" became popular at least in part because of technique -- you wanted to see how things happened as much as you wanted to see what happened -- while "Paranormal," for all its scares, is driven to a great extent by its storytelling and new plot turns.

Of course, the secret behind any franchise is that it offers something familiar. And so Paramount must walk a tricky line -- recycle the same stories and it will turn filmgoers off, but veer in too many new directions and people will wonder what happened to the "Paranormal" they know and love.

The studio has responded to this challenge by keeping the producing team intact for each film but hiring new directors each time out (this one, for instance, was directed by the documentarians Henry Joost and Ariel Schulman). The move is designed to provide a certain amount of slack; it allows, the studio hopes, for just the right amount of reinvention.

But there's already a question about whether "Paranormal" can continue achieving that magic balance. Despite the mega numbers for "Paranormal Activity 3," people actually didn't like what they saw: The movie notched a sub-par C+ grade on CinemaScore.

That "Paranormal" is flourishing, particularly in the recently struggling world of horror, is a marvel. But creating a seven-film mainstay is hard, and one weekend, no matter how stupendous, is no guarantee that marvel will continue.